Star Trek: The Next Generation – Reunion [4.7]

The dying Klingon Chancellor K’mpec requests that Picard serve as the arbiter between the leading contenders to replace him as leader of the Empire.  At the same time, K’Ehleyr returns to the Enterprise with her child, Alexander

Star Trek: The Next Generation – Sins of the Father [3.17]

Kurn, a Klingon officer on board the Enterprise in an officer exchange program, reveals himself to be Worf’s heretofore unknown brother.  Kurn shares with Worf of a danger to their family honor which only he can address back on the Klingon homeworld.